The biggest threats over these years have been new competition from traditional landline phone companies entering the pay-TV industry and, more recently, the Internet video streamers such as Netflix and Hulu.
At the moment, Comcast seems to have battled the telephone companies to a standstill in markets where they compete head-to-head. The telephone companies also have slowed their pay-TV expansion to focus on smartphones and fast-growing wireless services.
Video consumers, meanwhile, seem to be using Internet streaming services to broaden their entertainment options rather than using them to replace cable TV.
Craig Moffett, a leading telecommunications analyst with Sanford C. Bernstein & Co. L.L.C., called Comcast's low subscriber losses a "real shocker" and noted in a newsletter that subscriber trends "are likely to continue to gather momentum." Such an outcome was "unthinkable in consensus numbers as recently as six months ago," he wrote. "That's a HUGE change."
John C. Hodulik, telecommunications analyst with UBS Securities L.L.C., said in a conference call with Comcast executives that the 17,000 losses "should be a great harbinger of things to come."
Cable division president Neil Smit said in the same conference call that he did not believe Comcast could add subscribers in the first quarter because of rate-increase headwinds, but he did not dampen speculation about additions later in the year.
Comcast's stock soared 4.7 percent, or $1.27, to close at $28.52 a share with the subscriber news disclosed Wednesday in the company's fourth-quarter and full-year earnings report.
As part of the report, Comcast said it would boost its annual dividend 44 percent to 65 cents a share and repurchase $6.5 billion in company shares, with $3 billion of it spent this year.
Comcast revenue rose 3 percent to $15.04 billion for the quarter ended Dec. 31 and net income soared 45 percent to $1.3 billion because of the addition of the NBCUniversal news and entertainment conglomerate. The revenue figures were adjusted on a pro forma basis, as if Comcast owned NBCUniversal in 2010 and 2011, even though the deal closed in early 2011.
For all of 2011, Comcast reported $57.7 billion in revenue and net income of $4.2 billion.
Free cash flow - which can be used for dividends, the share-repurchase plan, capital investments, or acquisitions - soared more than 60 percent to $1.9 billion in the fourth quarter. Comcast has said it may have diminishing needs for big capital investments because it has already upgraded its communications network and no longer needs big investments to boost Internet speeds and improve TV quality.
A continuing segment of growth for Comcast has been broadband, and the company added 336,000 high-speed Internet subscribers in the fourth quarter, compared with 292,000 Internet additions in the year-ago period.
Comcast said the average customer spent $141.24 a month for their cable bill because of product bundles and enhanced services.
NBCUniversal, the entertainment and news conglomerate that Comcast acquired in early 2011, struggled with revenue declines in broadcast TV and movies in the fourth quarter. NBCUniversal's theme park and cable networks grew steadily over the period.
Brian L. Roberts, chairman and chief executive officer, said in an interview, "It's a culmination of a lot of work for a number years and it really came together in the fourth quarter and year."
Contact staff writer Bob Fernandez at 215-854-5897 or email@example.com.